LATERAL-MODE BEHAVIOR OF REACTIVE-ION-ETCHED STABLE-RESONATOR SEMICONDUCTOR-LASERS

We report experimental results on monolithic stable-resonator semicond uctor lasers. Curved end mirrors defining a near-concentric stable res onator were fabricated on wide-stripe GaAs/AlGaAs GRINSCH-SQW lasers u sing reactive-ion-etching. These lasers oscillate in close to the expe cted lowest-order Gaussian stable-resonator modes at threshold, evolvi ng into a coherent superposition of higher-order modes as the pump cur rent is increased up to two to three times threshold. At higher pump c urrents nonlinear defocusing effects cause the resonators to become ge ometrically unstable so that the lateral modes are determined by both the resonator geometry and the saturated gain and index profile. (C) 1 995 American Institute of Physics.